165636901 has 8 divisors (see below), whose sum is σ = 171060344. Its totient is φ = 160263360.

The previous prime is 165636881. The next prime is 165636907. The reversal of 165636901 is 109636561.

It is a Cunningham number, because it is equal to 12870²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1 + 165636900 = 1^2 + 12870^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165636901 - 2⁷ = 165636773 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165636907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5670 + ... + 19063.

It is an arithmetic number, because the mean of its divisors is an integer number (21382543).

Almost surely, 2^165636901 is an apocalyptic number.

It is an amenable number.

165636901 is a deficient number, since it is larger than the sum of its proper divisors (5423443).

165636901 is a wasteful number, since it uses less digits than its factorization.

165636901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24951.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 165636901 is about 12870.0000388500. Note that the first 4 decimals coincide. The cubic root of 165636901 is about 549.1854620512.

The spelling of 165636901 in words is "one hundred sixty-five million, six hundred thirty-six thousand, nine hundred one".